I'm more apt to believe the latter. No one seemed particularly passionate about the Lottery in the story. Not to the degree that someone speaking out against it would really have a negative effect.

I think it's more a matter of bystander effect (I had to study this in Psych where we dropped something in a crowd to see if anyone would pick it up, usually no one would even stop to help.)

No one gives a crap. They know the only reason she's objecting is because she feels it wasn't picked "fairly."
She starts screeching and becomes an annoying bitch so they finally stone her just to shut her up.
*smirk*

Karina Black//Slyth...errr... Ravenclaw.